package com.eclink.asset.hardware.server;

import com.eclink.asset.hardware.enums.HardwareServerStateEnum;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.Channel;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.CharsetUtil;
import lombok.extern.slf4j.Slf4j;
import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;

/**
 * I/O数据读写处理类
 *
 * @author chenshixian
 */
@Slf4j
public class ServerChannelInboundHandlerAdapter extends ChannelInboundHandlerAdapter {


    private int getLocalPort(ChannelHandlerContext ctx) {
        Channel channel = ctx.channel();
        InetSocketAddress local =  (InetSocketAddress) channel.localAddress();
        return local.getPort();
    }

    /**
     * 从客户端收到新的数据时，这个方法会在收到消息时被调用
     *
     * @param ctx
     * @param msg
     */
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception, IOException {



        // 这里是在前面的DelimiterBasedFrameDecoder转为了ByteBuf，验证是否是ByteBuf
        if (msg instanceof ByteBuf) {
            ByteBuf byteBuf = (ByteBuf) msg;
            try {
                String receivedData = byteBuf.toString(CharsetUtil.UTF_8);
                // 接收完整数据
                handleReceivedData(getLocalPort(ctx), receivedData);
            } finally {
                // 释放 ByteBuf 占用的资源
                byteBuf.release();
                // 回复消息
                ctx.writeAndFlush(Unpooled.copiedBuffer("Channel Read over", CharsetUtil.UTF_8));
            }
        }
    }
    private void handleReceivedData(Integer port, String receivedData) {

        System.out.println("received data: " + receivedData);

        ServerHolder.saveServerMessage(port, receivedData);

        // 数据处理
        // 这里如果想实现spring中bean的注入，可以用geBean的方式获取
    }

    /**
     * 从客户端收到新的数据、读取完成时调用
     *
     * @param ctx
     */
    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws IOException {
        log.info("channelReadComplete");
        ctx.writeAndFlush(Unpooled.copiedBuffer("Channel Read Complete over", CharsetUtil.UTF_8));
    }
    /**
     * 当出现 Throwable 对象才会被调用，即当 Netty 由于 IO 错误或者处理器在处理事件时抛出的异常时
     *
     * @param ctx
     * @param cause
     */
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws IOException {
        cause.printStackTrace();
        ctx.close();// 抛出异常，断开与客户端的连接
    }
    /**
     * 客户端与服务端第一次建立连接时 执行
     *
     * @param ctx
     * @throws Exception
     */
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception, IOException {
        super.channelActive(ctx);
        ctx.channel().read();

        Channel channel = ctx.channel();
        ServerHolder.activeServer(getLocalPort(ctx));
        InetSocketAddress socket = (InetSocketAddress) channel.remoteAddress();
        InetAddress address = socket.getAddress();
        String clientIp = address.getHostAddress();
        // 此处不能使用ctx.close()，否则客户端始终无法与服务端建立连接
        System.out.println("channelActive:" + clientIp + ctx.name());


        // 这里是向客户端发送回应
        ctx.writeAndFlush(Unpooled.copiedBuffer("Channel Active over", CharsetUtil.UTF_8));
    }

    /**
     * 客户端与服务端 断连时 执行
     *
     * @param ctx 上下文
     */
    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception, IOException {
        super.channelInactive(ctx);

        Channel channel = ctx.channel();
        ServerHolder.inactiveServer(getLocalPort(ctx));

        InetSocketAddress socket = (InetSocketAddress) channel.remoteAddress();
        String clientIp = socket.getAddress().getHostAddress();
        // 断开连接时，必须关闭，否则造成资源浪费，并发量很大情况下可能造成宕机
        ctx.close();

        log.info("channelInactive:{}", clientIp);
    }
    /**
     * 服务端当read超时, 会调用这个方法
     *
     * @param ctx
     * @param evt
     * @throws Exception
     */
    @Override
    public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception, IOException {
        super.userEventTriggered(ctx, evt);
        InetSocketAddress socket = (InetSocketAddress) ctx.channel().remoteAddress();
        String clientIp = socket.getAddress().getHostAddress();
        ctx.close();// 超时时断开连接
        log.info("userEventTriggered:" + clientIp);
    }
    @Override
    public void channelRegistered(ChannelHandlerContext ctx) throws Exception {
        log.info("channelRegistered");
    }
    @Override
    public void channelUnregistered(ChannelHandlerContext ctx) throws Exception {
        log.info("channelUnregistered");
    }
    @Override
    public void channelWritabilityChanged(ChannelHandlerContext ctx) throws Exception {
        log.info("channelWritabilityChanged");
    }
}
